1. Field
Example embodiments relate generally to photo masks, and more particularly to photo masks for manufacturing thin film transistor substrates and methods of manufacturing the photo masks.
2. Description of the Related Art
A liquid crystal display (“LCD”) apparatus is an example of a flat panel display (“FPD”), which has recently been broadly used. Other examples of the FPD include, but are not limited to, a plasma display panel (“PDP”) and an organic light emitting display (“OLED”).
The LCD apparatus applies voltages to molecules of liquid crystal to adjust arrangements of the molecules thereby changing optical characteristics of a liquid crystal cell such as birefringence, optical activity, dichroism and light scattering to display an image.
The LCD apparatus includes a LCD panel displaying an image. In the LCD panel, a wire pattern is formed to include metal, and the wire pattern is formed by an exposure process and an etching process using a mask.
Recently, as a width of the wire pattern has reduced, a width of a photo pattern for forming the line pattern has also reduced. However, it is difficult to form the pattern below the resolution limit of a general exposure machine.
In order to reduce the width of the photo pattern, it can be considered to apply a high photosensitive photoresist and enhance the limit resolution of the exposure machine. However, a process cost may increase according to an excessive use of the exposure machine. Accordingly, in order to reduce the process cost, enhancement of exposure efficiency in an exposure process and a lifespan of the exposure machine are required.